Several small gaps in the sequence of horse carbonic anhydrase D (low activity type) covering residues 119-123, 142-144, and 214-222 will be completed. Investigations of the primary structure of horse carbonic anhydrase C1 (high activity type) will be extended. Search for the presence of a C-terminal seven amino acid segment in bovine superoxide dismutase possibly lost during its isolation will be investigated. Completion of the primary structure of the human enzyme will be carried out. Better methods for the isolation of human and rat alpha fetoproteins by milder methods than usually employed will be continued. The role of the fatty acids found on the human isolate in either suppressing or augmenting certain lymphocyte function tests will be investigated. The fatty acid free protein will be reconstituted with specific fatty acids to detrmine if they confer specificity in the above type of activities. Fatty acid free human serum albumin reconstituted with the same fatty acids will serve as a control in these studies. The alpha fetoprotein of rats derived from animals with transplantable hepatomas, from pregnant animals and term fetuses will serve as an animal model.